Contents:
Transformations
Translation : (x, y, z)
$$
\begin{bmatrix}
1 & 0 & 0 & x \\
0 & 1 & 0 & y \\
0 & 0 & 1 & z \\
0 & 0 & 0 & 1
\end{bmatrix}
$$
Scale : (x, y, z)
$$
\begin{bmatrix}
x & 0 & 0 & 0 \\
0 & y & 0 & 0 \\
0 & 0 & z & 0 \\
0 & 0 & 0 & 1
\end{bmatrix}
$$
Rotation x :
$$
\begin{bmatrix}
1 & 0 & 0 & 0 \\
0 & cos(\theta) & -sin(\theta) & 0 \\
0 & sin(theta) & cos(theta) & z \\
0 & 0 & 0 & 1
\end{bmatrix}
$$
Rotation y :
$$
\begin{bmatrix}
cos(\theta) & 0 & sin(\theta) & 0 \\
0 & 1 & 0 & 0 \\
-sin(\theta) & 0 & cos(theta) & z \\
0 & 0 & 0 & 1
\end{bmatrix}
$$
Rotation z :
$$
\begin{bmatrix}
cos(\theta) & -sin(\theta) & 0 & 0 \\
sin(theta) & cos(theta) & 0 & 0 \\
0 & 0 & 1 & z \\
0 & 0 & 0 & 1
\end{bmatrix}
$$
Vertex Specifications
Specify vertex data.
- Create buffer Data: const float vertexPositions[] = {...}
- Initialize vertex Buffer:
glGenBuffers(1, &posiionBufferObject)glbindbuffer(GL_ARRAY_BUFFER, positionbufferObject)glbufferData(GL_ARRAY_BUFFER, sizeof(vertexpositions), vertexpositions, BufferobjectUsageHint)- BufferobjectUsagehint:
GL__STATIC_DRAW: Static data, only intend to set it onceGL_STREAM_DRAW: Dynamic data, intend to update it constantly, generally once per frame
- BufferobjectUsagehint:
glbindbuffer(0)
- Specify vertex data:
glbindbuffer(GL_ARRAY_BUFFER, positionbufferobject)glenablevertexattribarray(0)glvertexattribarray(0, 4, GL_FLOAT, GL_FALSE, 0, 0)
- Display:
gldrawarrays(GL_TRIANGLES, 0, 3)
glbufferSubData(): Change buffer data value
Vertex Array Objects: OpenGL Objects that store all of the state needed to make one or more draw calls. This includes attribute array setup information from glVertexAttribArray , buffer objects used for attribute arrays, and GL_ELEMENT_ARRAY_BUFFER binding, which is a buffer object that stores the index arrays, if needed
Pipeline
- Vertex Specification
- Vertex Proocessing and Vertex Shader
- Culling
- Rasterization
- Fragment Processing
Comments
comments powered by Disqus